Abstract

At ultralow fields of magnetic flux density, nuclear magnetic resonance spectra of a resolution well below were obtained, which is beyond what usually is achieved in the conventional high-field regime. The spectral resolution of our setup allows for the direct observation of the natural linewidth of distilled water. For heteronuclear systems, this enables pure J-spectroscopy in the absence of a chemical shift, with a resolution that is limited only by the natural width of the resonance lines.

Received 10 February 2005Accepted 14 June 2005Published online 27 July 2005

Acknowledgments:

The authors acknowledge the expertise of Dirk Gutkelch, who manufactured the mechanical setup. Thanks also to Sven Macholl for providing supporting high-field data and helpful discussions, and to Hans Koch for his steady encouragement and advice.